/*
 * Copyright (C) 2012 Christian Baum DHBW Stuttgart
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package DHBW.BT;

import DHBW.App.*;
import DHBW.BT.*;
import DHBW.Convert.*;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.UUID;

import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothSocket;
import android.content.Context;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.util.Log;

/**
 * This class does all the work for setting up and managing Bluetooth
 * connections with other devices. It has a thread that listens for
 * incoming connections, a thread for connecting with a device, and a
 * thread for performing data transmissions when connected.
 */
public class BluetoothDHBW {
    // Debugging
    private static final String TAG = "BluetoothDHBW";
    private static final boolean D = true;

    // Unique UUID for this application - UUID is Dummy ...
    private static final UUID MY_UUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");

    // Member fields
    private final BluetoothAdapter mAdapter;
    private final Handler mHandler;
    private ConnectThread mConnectThread;
    private ConnectedThread mConnectedThread;
    private int mState;
    private boolean mContinuous = false;
    private boolean mNew = false;
    
    // Constants that indicate the current connection state
    public static final int STATE_NONE = 0;       // we're doing nothing
    public static final int STATE_CONNECTING = 1; // now initiating an outgoing connection
    public static final int STATE_CONNECTED = 2;  // now connected to a remote device
    
    // Description for Position in array of received data
    private static final int ARRAY_CURRENT = 0;
    private static final int ARRAY_HOLD = 1;
    
    // Message types sent from the BluetoothChatService Handler
    public static final int MESSAGE_STATE_CHANGE 	= 11;
    public static final int MESSAGE_NOTICE			= 12;
    public static final int MESSAGE_DEVICE_NAME 	= 13;
    public static final int MESSAGE_NEW				= 14;
    public static final int MESSAGE_START_CONT		= 15;
    
    // Array of received data from pedelec
    private PedelecFrame[] mPedelecFrames = new PedelecFrame[2];
    
    /**
     * Constructor. Prepares a new BluetoothChat session.
     * @param context  The UI Activity Context
     * @param handler  A Handler to send messages back to the UI Activity
     */
    public BluetoothDHBW(Context context, Handler handler) {
        mAdapter = BluetoothAdapter.getDefaultAdapter();
        mState = STATE_NONE;
        mHandler = handler;
        mPedelecFrames[ARRAY_CURRENT] = new PedelecFrame();
        mPedelecFrames[ARRAY_HOLD] = new PedelecFrame();
    }

    /**
     * Set the current state of the chat connection
     * @param state  An integer defining the current connection state
     */
    private synchronized void setState(int state) {
        if (D) Log.d(TAG, "setState() " + mState + " -> " + state);
        mState = state;
        
        // Give the new state to the Handler so the UI Activity can update
        mHandler.obtainMessage(MESSAGE_STATE_CHANGE, state, -1).sendToTarget();
    }

    /**
     * Return the current connection state. */
    public synchronized int getState() {
        return mState;
    }

    /**
     * Start the chat service. Specifically start AcceptThread to begin a
     * session in listening (server) mode. Called by the Activity onResume() */
    public synchronized void start() {
        if (D) Log.d(TAG, "start");

        // Cancel any thread attempting to make a connection
        if (mConnectThread != null) {mConnectThread.cancel(); mConnectThread = null;}

        // Cancel any thread currently running a connection
        if (mConnectedThread != null) {mConnectedThread.cancel(); mConnectedThread = null;}

        // Start the thread to listen on a BluetoothServerSocket
        setState(STATE_NONE);
    }

    /**
     * Start the ConnectThread to initiate a connection to a remote device.
     * @param device  The BluetoothDevice to connect
     */
    public synchronized void connect(BluetoothDevice device) {
        if (D) Log.d(TAG, "connect to: " + device);

        // Cancel any thread attempting to make a connection
        if (mState == STATE_CONNECTING) {
            if (mConnectThread != null) {mConnectThread.cancel(); mConnectThread = null;}
        }

        // Cancel any thread currently running a connection
        if (mConnectedThread != null) {mConnectedThread.cancel(); mConnectedThread = null;}
        
        // Start the thread to connect with the given device
        mConnectThread = new ConnectThread(device);
        
        setState(STATE_CONNECTING);
        
        mConnectThread.start();
    }

    /**
     * Start the ConnectedThread to begin managing a Bluetooth connection
     * @param socket  The BluetoothSocket on which the connection was made
     * @param device  The BluetoothDevice that has been connected
     */
    public synchronized void connected(BluetoothSocket socket, BluetoothDevice device) {
        if (D) Log.d(TAG, "connected");

        // Cancel the thread that completed the connection
        if (mConnectThread != null) {mConnectThread.cancel(); mConnectThread = null;}

        // Cancel any thread currently running a connection
        if (mConnectedThread != null) {mConnectedThread.cancel(); mConnectedThread = null;}
        
        // Start the thread to manage the connection and perform transmissions
        mConnectedThread = new ConnectedThread(socket);
        
        setState(STATE_CONNECTED);
        
        mConnectedThread.start();

        // Send the name of the connected device back to the UI Activity
        Message msg = mHandler.obtainMessage(MESSAGE_DEVICE_NAME);
        Bundle bundle = new Bundle();
        bundle.putString(DHBW_BT_TestActivity.DEVICE_NAME, device.getName());
        msg.setData(bundle);
        mHandler.sendMessage(msg);
        
        
    }

    /**
     * Stop all threads
     */
    public synchronized void stop() {
        if (D) Log.d(TAG, "stop");
        if (mConnectThread != null) {mConnectThread.cancel(); mConnectThread = null;}
        if (mConnectedThread != null) {mConnectedThread.cancel(); mConnectedThread = null;}
        setState(STATE_NONE);
    }

    /**
     * Write to the ConnectedThread in an unsynchronized manner
     * @param out The bytes to write
     * @param length Length of message data
     * @see ConnectedThread#write(byte[])
     */
    public void write(byte[] out, int length) {
        // Create temporary object
        ConnectedThread r;
        int temp = mState;
        // Synchronize a copy of the ConnectedThread
        synchronized (this) {
            if (mState != STATE_CONNECTED) return;
            r = mConnectedThread;
        }
        // Perform the write unsynchronized
        r.write(out, length);
        int abc = 4;
    }
    
    /**
     * Waits in normal mode until new data is received
     */
    private void wait4BTAnswer() {
    	while (mNew == false) {
        	// Wait
        }
    	mNew = false;
    }
    
    /**
     * This function requests data from the pedelec 
     * @param param message ID of the request (list see PedelecFrame)
     */
    private void get(int param) {
    	byte[] tmp = new byte[1];
   	
    	if (mState == STATE_CONNECTED) {
    		tmp[0] = (byte) param;
    		write(tmp,1);
    	}
    }
    
    /**
     * Requests RPM from the pedelec
     * @return RPM
     */
    public int getRPM() {
    	if (!mContinuous) {
    		get(PedelecFrame.ID_RPM);
    		wait4BTAnswer();
    	}
    	return mPedelecFrames[ARRAY_CURRENT].rpm();
    }
    
    /**
     * Requests current from the pedelec
     * @return Current
     */
    public int getCurrent() {
    	if (!mContinuous) {
    		get(PedelecFrame.ID_CURRENT);
    		wait4BTAnswer();
    	}
    	return mPedelecFrames[ARRAY_CURRENT].current();
    }
    
    /**
     * Requests voltage from the pedelec
     * @return Voltage
     */
    public int getVoltage() {
    	if (!mContinuous) {
    		get(PedelecFrame.ID_VOLTAGE);
    		wait4BTAnswer();
    	}
    	return mPedelecFrames[ARRAY_CURRENT].voltage();
    }
    
    /**
     * Requests temperature from the pedelec
     * @return Temperature
     */
    public int getTemperature() {
    	if (!mContinuous) {
    		get(PedelecFrame.ID_TEMPERATURE);
    		wait4BTAnswer();
    	}
    	return mPedelecFrames[ARRAY_CURRENT].temperature();
    }
    
    /**
     * Returns whether Continuous value is activated
     * @return true = continuous
     */
    public boolean getContinuous() {
    	return mContinuous;
    }
    
    /**
     * Sends the request to (de)activate Continuous mode
     * @param newState true = continuous
     */
    public void setContinuous(boolean newState) {
    	byte[] tmp = new byte[2];
    	tmp[0] = 0x30;
    	if (newState == true) {
    		tmp[1] = 0x01;
    	} else {
    		tmp[1] = 0x00;
    	}
    	write(tmp,2);
    	int sdef = 3;
    }
    
    /**
     * Indicate that the connection attempt failed and notify the UI Activity.
     */
    private void connectionFailed() {
        setState(STATE_NONE);

        // Send a failure message back to the Activity
        Message msg = mHandler.obtainMessage(MESSAGE_NOTICE);
        Bundle bundle = new Bundle();
        bundle.putString(DHBW_BT_TestActivity.TOAST, "Unable to connect device");
        msg.setData(bundle);
        mHandler.sendMessage(msg);
    }

    /**
     * Indicate that the connection was lost and notify the UI Activity.
     */
    private void connectionLost() {
        setState(STATE_NONE);

        // Send a failure message back to the Activity
        Message msg = mHandler.obtainMessage(MESSAGE_NOTICE);
        Bundle bundle = new Bundle();
        bundle.putString(DHBW_BT_TestActivity.TOAST, "Device connection was lost");
        msg.setData(bundle);
        mHandler.sendMessage(msg);
    }

    /**
     * This thread runs while attempting to make an outgoing connection
     * with a device. It runs straight through; the connection either
     * succeeds or fails.
     */
    private class ConnectThread extends Thread {
        private final BluetoothSocket mmSocket;
        private final BluetoothDevice mmDevice;

        public ConnectThread(BluetoothDevice device) {
            mmDevice = device;
            BluetoothSocket tmp = null;

            // Get a BluetoothSocket for a connection with the
            // given BluetoothDevice
            try {
                tmp = device.createRfcommSocketToServiceRecord(MY_UUID);
            } catch (IOException e) {
                Log.e(TAG, "create() failed", e);
            }
            mmSocket = tmp;
        }

        public void run() {
            Log.i(TAG, "BEGIN mConnectThread");
            setName("ConnectThread");

            // Always cancel discovery because it will slow down a connection
            mAdapter.cancelDiscovery();

            // Make a connection to the BluetoothSocket
            try {
                // This is a blocking call and will only return on a
                // successful connection or an exception
                mmSocket.connect();
            } catch (IOException e) {
                connectionFailed();
                // Close the socket
                try {
                    mmSocket.close();
                } catch (IOException e2) {
                    Log.e(TAG, "unable to close() socket during connection failure", e2);
                }
                // Start the service over to restart listening mode
                BluetoothDHBW.this.start();
                return;
            }

            // Reset the ConnectThread because we're done
            synchronized (BluetoothDHBW.this) {
                mConnectThread = null;
            }

            // Start the connected thread
            connected(mmSocket, mmDevice);
        }

        public void cancel() {
            try {
                mmSocket.close();
            } catch (IOException e) {
                Log.e(TAG, "close() of connect socket failed", e);
            }
        }
    }
    
    /**
     * This thread runs during a connection with a remote device.
     * It handles all incoming and outgoing transmissions.
     */
    private class ConnectedThread extends Thread {
        private final BluetoothSocket mmSocket;
        private final InputStream mmInStream;
        private final OutputStream mmOutStream;
        private PedelecFrame tempFrame = new PedelecFrame();

        public ConnectedThread(BluetoothSocket socket) {
            Log.d(TAG, "create ConnectedThread");
            mmSocket = socket;
            InputStream tmpIn = null;
            OutputStream tmpOut = null;

            // Get the BluetoothSocket input and output streams
            try {
                tmpIn = socket.getInputStream();
                tmpOut = socket.getOutputStream();
            } catch (IOException e) {
                Log.e(TAG, "temp sockets not created", e);
            }

            mmInStream = tmpIn;
            mmOutStream = tmpOut;

        }

        public void run() {
            Log.i(TAG, "BEGIN mConnectedThread");
            byte[] buffer = new byte[8];
            int count = -1;
            int identifier = -1;
            int max = -1;
            int input = -1;
  
            try {
				sleep(250);
			} catch (InterruptedException e2) {
				// TODO Auto-generated catch block
				e2.printStackTrace();
			}
            
            setContinuous(true);
                   
            // Keep listening to the InputStream while connected
            while (true) {
                try {
                    // Read from the InputStream
                    input = mmInStream.read();
                    
                    if (input != -1) {
                    	if (count > 0) {
                    		buffer[count-1] = (byte) (input);
                    		
                    		if (count == max) {
                    			if (identifier==0) {
                    				if ((buffer[0] & 0x01) == 0x01) {
                    					mContinuous = true;
                    					tempFrame.clearData();
                    				} else {
                    					mContinuous = false;
                    				}
                    			}                    			
                    			mPedelecFrames[ARRAY_CURRENT].setData(identifier, max, buffer);
                    			mNew = true;
                    			tempFrame.setData(identifier, max, buffer);
                    			Log.d(TAG,"New message: ID="+identifier+", MAX="+max+", BUFFER[0]="+buffer[0]);
                    			if (identifier == PedelecFrame.MAX_USED_ID && mContinuous) {
                    				mPedelecFrames[ARRAY_HOLD].importData(tempFrame);
                    				mHandler.obtainMessage(MESSAGE_NEW, tempFrame).sendToTarget();
                    			}
                    			
                    			count = -1;
                    			input = -1;
                    		} else {
                    			count++;
                    		}
                    	}

                    	if (count == 0) {
                    		identifier = input & 0x1F;
                    		max = input & 0xE0;
                    		max = max >> 5;
                    		count = 1;
                    	}
                    	
                    	if (count == -1) {
                    		if (input == 0x10) {
                    			count = 0;
                    		}
                    	}
                   	
                    } 
                } catch (IOException e) {
                    Log.e(TAG, "disconnected", e);
                    connectionLost();
                    break;
                }
            }
        }

        /**
         * Write to the connected OutStream.
         * @param buffer  The bytes to write
         */
        public void write(byte[] buffer, int length ) {
            try {
            	mmOutStream.write(MessageConverter.convertOut(buffer, length));
            } catch (IOException e) {
                Log.e(TAG, "Exception during write", e);
            }
        }
        
        public void cancel() {
            try {
                mmSocket.close();
            } catch (IOException e) {
                Log.e(TAG, "close() of connect socket failed", e);
            }
        }
    }
}
